Bump docker-app to v0.8.0-rc1

Signed-off-by: Silvin Lubecki <silvin.lubecki@docker.com>
Upstream-commit: 47a17b7b01b73f1b86c48350bc9feb4f68406e38
Component: packaging

Author: silvin-lubecki

components/packaging/plugins/app.installer

@@ -6,7 +6,7 @@ source "$(dirname "$0")/.common"
 
 GOPATH=$(go env GOPATH)
 REPO=https://github.com/docker/app.git
-COMMIT=v0.8.0-beta2
+COMMIT=v0.8.0-rc1
 DEST=${GOPATH}/src/github.com/docker/app
 
 build() {